OK, I have been looking into an amp to go between my (new to me) passive
sub and my (6 mo old) A/V Receiver.

The Receiver has a single SUB output jack, but the speaker enclosure has
both L & R inputs, in fact it has outputs as well for I assume satellite
speakers if I so choose. (We'll ignore those.)

My plan is to add this sub to an existing setup that already had decent
Front, Center and Surround speakers.

My question this time around is how best to deal with a single Sub
Output from the source through an Amp and on to a Stereo (perhaps dual
voice coiled?) Subwoofer.

Here's what I've brainstormed already:

- Run just one channel of the Amp and the Sub, ignoring the other
winding in the speaker & the other channel of the amp.

- Find an Amp that will accept a single input and will in turn output to
stereo.

- Same as option #1, but use both speaker windings, basically changing
the Ohms rating.

- Find a Mono Amp and A) Use just one winding in the speaker, or of
course B) Single in, Single out but use both windings on the Sub.

What say ye?


TBerk

OK, I have been looking into an amp to go between my (new to me)
passive
sub and my (6 mo old) A/V Receiver.


The Receiver has a single SUB output jack, but the speaker enclosure
has
both L & R inputs, in fact it has outputs as well for I assume
satellite
speakers if I so choose. (We'll ignore those.)
_________________________________________________
The Reciever has an RCA connection marked sub out, correct?
If so just connect the RCA cables from there to the sub input which I
assume are also RCA connectors. Just to be sure, we are talking about
a powered subwoofer, correct?

The sub out from the reciever should already sum the LF to mono so no
need to worry further.

The only other setups I've seen are when the connections on the sub
woofer are for speaker wire input from the amp/reciever and outputs to
the main front speakers.

________________________________________________
My plan is to add this sub to an existing setup that already had decent

Front, Center and Surround speakers.


My question this time around is how best to deal with a single Sub
Output from the source through an Amp and on to a Stereo (perhaps dual
voice coiled?) Subwoofer.
__________________________________________________ ____
Just connect form the sub output on the reciever, to the input on the
sub. then you go about setting up the crossover on the sub to blend
with the main front speakers. It would be best (if you haven't already
purchased the sub) to get a sub that has both adjustable high and low
pass filter sections, failing that a passive sub with a separate amp
that has, (as many proamps do) a low pass filter and then add a high
pass filter. The reason for this, is to limit the LF output from the
main speakers and save them from working in their most difficult area.
Not having paid any attention to what the abilities are of an A/V
reciever I can't say if these sort of features are already built in,
but I'm sure the owners manual will tell you.
__________________________________________________ ____

If you buy a passive sub, or build one then you need an amp that can be
bridged to mono and preferably you need both high pass and low pass
functions to send only frequencies below a certain point (80Hz or less,
although the sub out will likely be 150-200 Hz) and send only
frequencies above a variable point to the main speakers. They need to
be variable and preferably the slopes should be 24 dB/octave to keep
the bass in the sub and not leak out.

www.hypex.nl has some of the best sub amps around.
Do a search for pro amplifiers and you will find there are many
affordable choices for bridgeable amps that will provide you with ample
power at lower prices than the typical sub amp. Then if you want to be
thourough, add a parametric EQ to smooth out probable FR bumps imposed
by the room.

Adire's Shiva and Tempest drivers are some of the best subwoofer
drivers available, and plans for cabinets are easy enough to find
through them as well. Another option in the DIY sub area is Rhythmik
Audio which also have a very godd product. If yo go the DIY route look
into the possiblity of using sonotube instead of an MDF cabinet. You
might wind up with a sub that looks something like a water heater, but
it will be at least as strong as a conventional cabinet and much
cheaper.

Adire also makes finished subs. Other good subs that are already
assembled are, HSU, PSB, NHT (who also sell there 12" woofer to the DIY
market for use in a sealed enclosure, the absolute easiest DIY project
there is), and SVS. All of these are good products and will give you
excellent bass.

Lastly you will need something that generates test tones so you can
match the sub to the mains, and an SPL meter to measure the levels so
you can match them for smooth integration.

You might want to check with the subwoofer section of www.diyaudio.com
and check the archives for some of the projects that have been done by
the participants.

There are plenty of online resources if you go the DIY route, which is
what I did. I'll never buy a ready made sub again, since I know you
can get equal or better performance by doing it yourself.

In , on 04/10/05
at 11:08 AM, T said:


[ ... ]
The Receiver has a single SUB output jack
[ ... ]

The RCA subwoofer output jack on a surround sound receiver is MONO and
any frequencies that don't belong to the subwoofer have been removed.
In the setup menu for the receiver, claim that the front and/or rear
speakers are "small" if you want bass that normally would be routed to
them to be withheld and routed to the subwoofer instead.

Assuming you have an appropriate amount of power and a capable
subwoofer, it doesn't matter if you use an external amplifier or an
amplifier built into the subwoofer.

The subwoofer is MONO even if it has a left and a right input.
Connecting to only the left or right input decreases the output level a
bit, but you can easily compensate for that by turning up the level
adjustment. (You will have to adjust the level anyway so that the
subwoofer output matches the main channels.)

A dual coil passive subwoofer appears as if it is two speakers. If you
use both coils, your amplifier will behave as if a second speaker has
been added. (Depending on who is lurking on the news group, this
statement may create some "flames". If it does, draw your own
conclusions after the flames have died down a bit.)

Passive subwoofers don't usually include level controls. Hopefully, the
gain of the external amplifier is variable or compatible with the
subwoofer output adjustment range of your receiver and the subwoofer
efficiency. It's a complex discussion when debating if the power
handling capability of the subwoofer would be much different when
driving one or both coils. True, the impedance seen by the amplifier is
different, but all the heat from the subwoofer coils is being dumped
into the same confined space in any case.

Make sure that the subwoofer's internal crossover does not fight with
the signal sent by the receiver.

-----------------------------------------------------------
spam:
wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13 (Barry Mann)
[sorry about the puzzle, spammers are ruining my mailbox]
-----------------------------------------------------------

Thank you both (Learning & Mann).

Some clarification from my end.

- I KNOW the A/V output is MONO.

- I have a Passive prebuilt SUB.

- It is a Paradigm SB-100.

Currently I don't have a stand alone amp for it, I am leaning towards
running the SUB output of the A/V unit through a vintage Sony Receiver I
have on the AUX input.

My dilemma is wrapped around having both Left & Right binding posts on
the bottom of the Sub cabinet. I'll likely ignore one side and just hook
up one or the other only.


TBerk

T wrote:
Thank you both (Learning & Mann).

Some clarification from my end.

- I KNOW the A/V output is MONO.

- I have a Passive prebuilt SUB.

- It is a Paradigm SB-100.

Currently I don't have a stand alone amp for it, I am leaning towards
running the SUB output of the A/V unit through a vintage Sony
Receiver I have on the AUX input.

My dilemma is wrapped around having both Left & Right binding posts on
the bottom of the Sub cabinet. I'll likely ignore one side and just
hook up one or the other only.

Does it also have L & R *output* terminals? If so, it probably has a dual
coil subwoofer driver and passive crossover. It can be placed directly on
the outputs of your amplifier, with your L&R front speakers connected to the
subwoofer outs. The crossover will handle the job of filtering some of the
low frequencies out of the main speakers and directing them to the sub...a
workable solution, but inefficient...some power will be wasted in the
crossover, and you might not want to filter the lows from your mains.

****Main amp speaker outssub insL&R speakers OR Main amp speaker outs
parallel with sub ins and L&R speakers (possible impedance problem?)****

The setup you describe, using an auxiliary sub amp, will result in slightly
more volume (assuming enough power output from that amp). Use a 'Y' cable
(one RCA male to two RCA males) to route sub output from your main amp to
the AUX ins on your sub amp, and connect the L&R speaker outs to your sub
ins.

***Main amp sub out'Y' cableL&R sub amp AUX inssub amp L&R speaker
outssub***

jak

TBerk

jakdedert wrote:

snip
Use a 'Y' cable (one RCA male to two RCA males)
to route sub output from your main amp to
the AUX ins on your sub amp, and connect the
L&R speaker outs to your sub ins.

***Main amp sub out'Y' cableL&R sub amp AUX inssub amp L&R speaker
outssub***

jak



MuHahahahahah. That was _exactly_ what I wanted to hear.

It's just to get the thing a little run. I'll be picking out a dedicated
stand alone amp down the line.


Thx everybody.
TBerk

"T" wrote in message
m...
jakdedert wrote:

snip
Use a 'Y' cable (one RCA male to two RCA males) to route sub output
from your main amp to
the AUX ins on your sub amp, and connect the L&R speaker outs to
your sub ins.

***Main amp sub out'Y' cableL&R sub amp AUX inssub amp L&R
speaker
outssub***

jak



MuHahahahahah. That was _exactly_ what I wanted to hear.

It's just to get the thing a little run. I'll be picking out a
dedicated stand alone amp down the line.

Check out PartExpress linear FET class AB sub amps. Nice units, good
value - I have two in service (home theatre and stage piano keyboard)
.. BTW, I have no connection with this company.
Cheers,
Roger

Engineer wrote:
"T" wrote in message
m...

jakdedert wrote:

snip

Use a 'Y' cable (one RCA male to two RCA males) to route sub output
from your main amp to
the AUX ins on your sub amp, and connect the L&R speaker outs to
your sub ins.

***Main amp sub out'Y' cableL&R sub amp AUX inssub amp L&R
speaker
outssub***

jak



MuHahahahahah. That was _exactly_ what I wanted to hear.

It's just to get the thing a little run. I'll be picking out a
dedicated stand alone amp down the line.


Check out PartExpress linear FET class AB sub amps. Nice units, good
value - I have two in service (home theatre and stage piano keyboard)
. BTW, I have no connection with this company.
Cheers,
Roger





Yeah, they seem to get a lot of recommendations.

I have know of them for awhile but just recently when i got up the
gumption to build a sub (and hence buy one of those amps) a friend
dropped this passive prebuilt sub on me for free so I was going to hook
it up and give it a run to see what I was working with.


Thx everybody,
TBerk

T Apr 14, 4:45 am show options

Newsgroups: rec.audio.tech
From: T


Some clarification from my end.


- I KNOW the A/V output is MONO.


- I have a Passive prebuilt SUB.


- It is a Paradigm SB-100.


Currently I don't have a stand alone amp for it, I am leaning towards
running the SUB output of the A/V unit through a vintage Sony Receiver
I
have on the AUX input.


My dilemma is wrapped around having both Left & Right binding posts on
the bottom of the Sub cabinet. I'll likely ignore one side and just
hook
up one or the other only.


TBerk


T: Just go to www.svssubwoofers and click on amps and EQ's. You find
2 Sampson amps that shoudl do very nicely for your sub. I think best
results would be obtained by adding an electronci xover and parametric
EQ, to flatten out the response.

Correction: make that www.svsubwoofers.com